Geocoding is a process of finding geographic coordinates (often expressed as latitude and longitude) that can be associated with other geographic data, such as a street address, a postal code, or a named land feature. Reverse geocoding can include finding geographic data, e.g., a street address, a postal code, or a named land feature to be associated with given geographic coordinates.
A mobile device, such as a smart phone, can include various hardware and software for determining current geographic coordinates of the mobile device, which can be used to identify geographic data (e.g., street address) of the mobile device through reverse geocoding. The current geographic coordinates determined by the mobile device can have various levels of accuracy. For example, a mobile device can include a receiver and software for determining a location using a global positioning system (e.g., a GPS system). GPS accuracy can be affected by a number of factors, including satellite positions, noise in a GPS signal, atmospheric conditions, and natural barriers between a GPS signal source and the mobile device. Noise can create an error between 1 to 10 meters. Objects such a mountains or buildings between a GPS satellite and the mobile device can also produce errors, sometimes up to 30 meters. The most accurate determination of position occurs when the satellite and receiver have a clear view of each other and no other objects interfere. However, a clear view is not always possible, for example, when the mobile device is located in a downtown area of a city where numerous high-rise buildings are present. In addition to GPS, the mobile device can use other technologies to determine the geographic coordinates, for example, by triangulating signals from wireless communications gateways, such as cellular signals from various cell towers of a cellular communications network. Like the GPS system, triangulating cellular signals or WiFi™ signals can produce the geographic coordinates with varied accuracy.